The problematic question of "what is craft beer?" has now had a philosopher get involved. Brewer & Distiller International magazine has an article from some time philosophy lecturer and Heriot-Watt brewing graduate Andrew Jorgensen addressing this.
Of course those of us at the cutting edge of beer nerdery have long since decided it's simply a marketing term but it's interesting to see the IBD discussing this topic.
In the article the Brewers Association official definition is dissected and found lacking, and the usual guff about "passion" is dismissed as being too vague and usable by anyone. Instead what philosophers call "Direction-of-Fit" is called in to play:
"For a beer to sell well and be successful there needs to be a match between the attributes of the beer and the taste of the public. But there are two ways this 'fit' can be achieved. Either the beer takes its direction from and is designed to fit people's tastes. This is a beer-to-public direction-of-fit because the fit is achieved by making beer that conforms to people's tastes. Or the beer is made according to the brewer's tastes but s/he hopes to bring the public over to them. This is a public-to-beer direction-of-fit because people's tastes have to conform to the attributes of the beer if the brewer's desire to brew a successful beer is to be realised."
Though different philosophies might be at work, I still don't see this how this actually makes "craft beer" something distinct from other beer, as surely a brewer doesn't have to consistently stick to one of the philosophies and in his or her range of beers they could have some that are "beer-to-public" and some that are "public-to-beer".
I remember a conversation I had a few years back with the last Head Brewer of Young's. He described Young's Special London Ale, an excellent IPA of 6.4% ABV, as a "brewer's beer" because it was the sort of beer brewers make to their own taste, not the taste of the public. This seems to closely match with the "two philosophies" idea but though the philosophies behind Young's Special London Ale and Young's "Ordinary" may be different they both come from the same brewery.
"Craft" beer and "non-craft" beer may be aimed at different markets but really that just seems to confirm that "craft beer" is just a marketing term. Some breweries focus on one type of beer, some on the other, and some do both.